I got an email detailing a possible escape from this situation from my undercover sources.

Look at the picture above. Imagine the top man is under the armpit. Basically the situation Ritchie described.

One quick jerk to the right, this will cause the top man to base with his right arm. This relieves pressure from his elbow that would usually be squeezing from hip to elbow. Use this moment to turn LEFT. And then KEEP TURNING left. Basically ducking your head, going belly down. Once you curled up you can release the leg and you will be in a neutral position with both of you on your knees. The description from what to do here is cloudy. I will clarify the details with another email.

I've got a couple of suggestions:
1) Do the "lockdown" where you grapevine his caught leg with your own. Straighten out and shift his weight off your body. Use your right arm (you've got his right leg) to grab the back of his left arm and roll to your left to make him brace with his left hand. This should enable you to escape your left arm and get an underhook.

2) This is really simple - I worked it out last year but I'm not sure if it will work in this situation. You have your opponent's right leg caught. With your right hand, grab his belt and move your head away so your right arm is locked straight. As he escapes his leg (don't let him go onto mount, but let him escape to side control), keep your arm straight and move your hips away. Because your arm is straight he can't follow you, so you should be able to pull him back into your guard. I've used this move successfully a few times on a black belt 80lbs heavier than myself, so I know it works with a normal half-guard pass. I'm just not sure about the weight distribution effects with this pass, but I don't see why it wouldn't work. It also works no-gi if you grab the top of his shorts.

THAT is what I was TRYING to describe in my earier post, except that Saul Advocates the grabbing of the belt/shorts, rather than the control of the upper body to get out, his way is MUCH better ( well DUH !!).
Funny thing, I was working on this yesterday with a buddy and, a few times I reached over and grabbed his belt, just because it was "there"...

I don't know anything about the escape, but thanks for the new half-guard pass! It worked great last night in Judo.

"Labor is prior to, and independent of, capital. Capital is only the fruit of labor, and could never have existed if labor had not first existed. Labor is the superior of capital, and deserves much the higher consideration." -A. Lincoln